Wrapping mechanism



Sept. 25, 1945. T. JENSEN WRAPPING MECHANISM Filed May 13, 1943 5Sheets-Sheet 1 INVENTOR THORMOD JENSEN ATTORNEY Sept. 25, 1945. T.JENSEN WRAPPING MECHANISM Filed May 13, 1943 5 Sheets-Sheet 2 PatentedSept. 25, 1945 WRAPPING MECHANISM Thormod Jensen, Laurelton, N. Y.,assignor to American Machine & Foundry Company, a corporatlon of NewJersey Application May 13, 1943, Serial No. 486,769

Claims. (Cl. 93-2) This invention relates to wrapping machines, moreparticularly to improvements in the construction of the back tensionplate and the mechanism for operating the lap roller.

One of'the main objects of the invention is to prevent slippage of thewrapper as it is draped about the girth of the article to be wrapped. Tothis end, the back tension plate, which is slid- .ably supported on thelifter table to press the wrapping material against the leading face ofan article delivered to the table, may be provided with a pad providedwith holes communieating with a suction chamber whereby the wrappingmaterial will be suctionally held against the pad until the desiredwrapper length is severed. Thus the wrapping material will be firmlyheld and slippage thereof will be prevented. In an alternativeconstruction selected to exemplify the invention, suction cups may bemounted on the back tension plate to hold the wrapping material. Witheither type of construction a saving of paper is possible, since thereis greater certainty that the exact length of wrapper required will besevered and therefore shorter wrapper lengths may be employed becausemore uniform overlaps are obtained. Therefore an excessively wideoverlap will not be required to provide for occasional slippage.

Another object of the invention is to" reduce the speed at which thewrapping material is drawn downwardly bythe-lap roller over the rearface of the article onflthe lifter tableand eliminate the jerlgy motionwhich is imparted to the lap roller by operating mechanism now employed.To this end the lap roller is moved downwardly at a speed which isapproximately 50% slower without dwelling at a midway point;

as heretofore, at which the severing of the wrapping material takesplace. Thus a slower continuous drag is exerted on the wrapping materialwhich in conjunction with the improved construction of the back tensionplate will further reduce lap variations and minimize compression ofsoft loaves.

In the accompanying drawings, which form a part of this specificationand in which like characters of reference indicate the same or likeparts: I 1

Fig. 1 is a sectional side elevation of a wrapping machine equipped withthe preferred form of back tension plate;

Fig. 2 is a plan view of the same taken from line 22 of Fig. 1;

Fig. 3 is a side elevation on an enlarged scale illustrating the suctionvalve control mechanism, taken on line 3-3 of Fi 2;

Fig. 4 is a sectional view taken from line 4-4 of Fig. 2;

Fig. 5 is a detail sectional view of the suction valve;

Fig. 6 is a cross-section of the valve taken on the line 6-6 of Fig. 5;

Fig. 7 is a detail view of a modified form of the invention, illustratedin a view similar to Fig. 3.

Referring to Figs, 1-4 of the drawings, the side frames III of thewrapping machine support a cam shaft I2 which carries a gear I securedthereon by a set screw I6 (Fig. 2). This gear is driven by another gearon the motor (not shown) of the machine. A cam 22 fixed to shaft l2 by aset screw 24 (Fig. 2) engages with a cam roller 26 supported on a stud28 fixed to an arm 30 of a cam lever 32 loosely mounted on a stationarycross shaft 34, supported in frames l0. Cam lever 32 has another arm 36which is connected by a stud 38 to an adjustable link 40 pivoted on astud 48 secured to a lifter table arm 50. Arm 5!] is loosely mounted ona stationary shaft 52 supported in frames Ill and secured therein by ascrew 54. In Fig. 1 the arm 50 is shown in an inclined position, andwhen moved by the action of cam 22, it is elevated to the horizontalposition indicated by broken lines.

On arm 50 is fastened a plate 58 on which is slidably mounted the base60. Base 60 is guided between two guide strips62 and 64 fixed to arm 50by screws 66. On guides 62 and 64 there is secured a cross piece 68carrying an upright rod 10 on which a bracket 12 is adjustably held byset screw 14, and on bracket 12 is mounted a top tension plate 16.

The slide or base 60 carries a bracket 18 fastened thereto by screws 80.To said bracket is secured a back tension plate 82 on which is fasteneda rubber suction pad 84. The latter has a plurality of holes 86, whichcommunicate through corresponding holes in back tension plate 82 with asuction chamber 88 formed in bracket 18.

A duct 90 extends from said chamber to the base of bracket 18. A two-waysuction valve 92 is provided with a nipple 94, through which itcommunicates through duct 90 with chamber 88 the nipple extendingthrough a slot in plate 58 and being screwed into bracket 18. The valvecock I I2 of said suction valve is free to rock from a position at whichits port I l2b is in communication with the port 92a and the bore innipple 94 to relieve the suction in the suction chamber 88 to a positionshown in Fig. at which it places the latter in communication with asource of suction through a nipple 96 thereof on which is mounted oneend of a flexible air-hose 98. The other end of the latter is mounted ona tube I00 fastened to lifter table arm 50 by clamps I02. The purpose ofsaid flexible hose is to compensate for the sliding movement which willbe described later. From tube I00, another flexible hose I03 extends toa stationary tube I04 leading to a source of suction I06, which mayconsist ofa vacuum tank T and a vacuum pump V driven by a motor lVIarranged as shown in Fig. l.

The angular movement of valve cock II2 from one position to the other,previously mentioned, is effected by means of a block provided with twofingers or cam lugs I08 and H0 and secured to the stem III of valve cockII2 which projects at one end of the valve seat formed in valve 92. Onthe other end of the valve cock is threaded a nut I I2a which maintainsthe cock in the valve seat. The finger I08 which turns cock II2 to theposition at which .suction is applied to chamber 88, is engaged at thelast part of the downward stroke 01' arm 50, by a finger I I4, pivotedon a stationary stud H6, and having an arm I I8 which is pivotallyconnected by a stud I20 to a link I22 connected by a stud I24 to one endof a bell-crank I26 pivoted on a stationary stud I28. On the other endof said bell-crank is pivotally mounted a link I30 connected by a studI32 to a feeler lever I34 fulcrumed on a stud I36 fastened in an arm I38of a stationary bracket I40. Said feeler lever has a feeler shoe I42positioned over a material feed'runway I44 in such a way that a breadloaf or other article being advanced on said runway by the flights of anendless conveyor (not shown), will raise said feeler "shoe" I42 up to aposition which, through the above described linkage, moves finger II4into the dotted position (shown in Fig. 3) where it may engage with camlug I08 during the descent of the lifter table and turn valve cock II2to the "suction on position shown in Fig. 5.

The flights of the endless conveyor pass through a slot I44a in therunway I44, and refernipples 94 and 96.

As shown in Fig. l, the feeler mechanism is normally in the inactiveposition and the weight of "shoe" I42 holds a lug I46 of the feeler shoeagainst a pin I48 secured in arm I38. The cam lug H0 is positioned toengage, when the back tension plate is moved backwardly with a camroller I50 mounted on a'stud 'I52secured to an arm I54 which is pivotedon a stud I56 secured in an extension I58 of arm 50 (Figs. 3 and 4). Atorsion spring I62 having one end fixed in the head of stud I56 and theother end held in arm I54 urges a lug I84 on said 'arm against a stoplug I68 on extension I58.

When cam lug III! is moved in the direction shown by the arrow (Fig. 3),during the displacement of the back tension plate by a package orarticledelivered upon the lifter table, said camlug IIO pushes the camroller I50 out of its way. In order to prevent the impact between themfrom shifting the valve cock II2, a stop I68 secured to slide 60 isprovided, said stop coacting with cam lug I 08 to limit the angularmovement of the valve cock. When cam lug H0 is moved in the gees-zooopposite direction, during the forward movement of the back tensionplate, it slides against and is thereby displaced upwardly by cam rollerI 50, which now is backed up by lug I86.

The valve cock II2 thereby is turned from the "suction on position shownin Fig. 5 to the suction off position, thereby placing the bore of thenipple 94 in communication with the port 82a of the valve 82 anddestroying the suction in the suction chamber 88.

The web of wrapping material ,W is guided from a roll of wrappingmaterial (not shown) over a stationary plate In and passes between apair of guid rollers I13 and I15 and hangs loosely in-front of a gapcloser I12 ready for an article to be wrapped therein. An article ismoved along on runway I44 by the flights of the endless conveyor (notshown) and thereby lifts shoe I42 so that the valve cock II2 will bemoved to fsuction on position during the descent of the lifter table.The package is then advanced by the pusher I10, which is slidablymounted in bracket I40 and actuated by mechanism not shown, forwardlyacross the gap-closer I12, into the position shown in Fig. 3 where thepackage has just brought the wrapping material into engagement with therubber suction pad 84 to cover the suction holes 86 thereof, wherebysaid wrapping material is held firmly, so that no slippage thereof willoccur while the package is still further advanced on to the lifter tableand comes into contact with the top tension plate 16 and while thelifter table swings upwardly to draw 011 an additional length from theroll suflicient to encompass the girth of the article.

After the back tension plate has thus been displaced to the limit of itsbackward movement, the

lifter table is moved up to the horizontal position shown in brokenlines (Fig. 1) where it dwells while the wrapping material is drawndownwardly over the rear side of the article by a lap roller I90operated by mechanism hereinafter described. At the same time thepackage is being advanced oil the lifter table by two transfer arms I14carried by two endless chains I18 running over pairs of sprockets (notshown), one pair of sprockets being suitably driven in timed relationwith the operation of the lifter table. Since the construction of thesetransfer arms and chains, and the mechanism for driving the same issimilar to that shown in the patent to F. R. Schmitt, No. 1,851,295,further description thereof is deemed unnecessary. The lower endsof saidtransfer arms I14 engage with the ledges I18 of back tension plate 82(Figs. 2 and 4) and thereby advance the package from the lifter tableover a roller I and the top of the operating arm I82 on which roller I80is supported, on to the delivery table I88. The arm I 82 is operated bysuitable mechanism such as shown in said patent to F. R. Schmitt, No.1,851,295, to cause the roller I80 to pinch the wrapping materialagainst a roller I84 on the lifter table before the package leaves thelifter table, and thus clamp the wrapping material while the lap rollerI descends to its lowermost position, the knife I88 cutting the wrappingmaterial while the lap roller is descending. Reference may also be hadto said patent for the details of the mechanism for operating knife I86.While the back tension plate is being returned to the initial positionby the transfer arms I14, the cam lug II 0 moves against cam roller I50and the suction valve .cock H2 is shifted to suction ofl" position,releasing the wrapping material from the suction pad 84. As

the lifter table now goes down, ledges I18 of-the back tension plate 82drop out of engagement with transfer arm I14 and the latter then engagethe package and forward it across arm I82 and on to the delivery table.In this manner the folding of the wrapper about the girth of the articleis completed when the outer bottom flap of the wrapper is wiped underthe bottom of the package by the front edge of the table I88, the rearand bottom end flaps being then folded by stationary folders. It may benoted that front flaps are folded in by tuckers (not shown) duringdelivery of the loaf P to the lifter table, and the top flaps are foldeddown by folders (not shown) during the ascent of the lifter table. Theposition of the back tension plate 82 when disengagement with transferarms I14 occurs, is such that it is ready for the next package and theposition 'of cam lug I08 is such that it will be engaged and valve stemII2 shifted to suction on position at the last part of the downwardmovement of arm 50.

If however, as previously described, there is no package present onmaterial feed runway I 44, the

finger II4 will remain in its normal position and consequently therewill be no suction on rubber suction pad 84. This latter'featureprevents the wrapping material hanging over the edge of gapcloser I12,from adhering to pad 84 and thereby being improperly positioned, if nopackage is present.

Fig. 7 shows a modified form of the invention wherein instead of asuction pad, the necessary suction is provided by a suction cup (orplurality of suction cups) 200. For *this purpose the cup 200 is mountedin a cone shaped opening formed in back tension plate 202 and has ashank projecting' through an opening in a supporting bracket 204 andsecured in the same by two halfwashers 203 fitted into a groove in theshank of cup 200 and'fastened to bracket 204 by screws 206. cup 200, itis provided with an axial hole 208, the outer end of which forms a seatfor a valve 2I0, secured by a screw 2I2 to an'arm 2I4 of a lever 2I6pivoted on: a stud 2I8 fixed in bracket 204.

The latter is fastened by screws 80a to slide 60a which 'is similar toslide 60 of the preferred form of the invention described above. Lever2I6 also has an arm 220, which carries a cam roller 222 pivoted on astud 224. Valve 2I0 is urged toward a closed position by a spring 226held at one end by a stud 228 fixed to arm 2I4 and at the other endhooked on to an angle piece 230 fastened by the lower screw 206. Thisvalve is controlled by means of a cam lug 232 of a cam piece 234 pivotedon a stud 236 held in a bracket 238 fastened by screws 240 to slide 60a.The latter is slidably mounted on alifter table 58a. secured to an arm50a, the mounting of table 58a on arm 50a and of slide 6011 on table 58abeing similar to that shown in Figs. 1 and 2. To close the valve 2)after it In order to relieve the suction in suction has been opened, ashereinafter described, cam

lug 232 coacts during the descent of lifter table I 58a with a stopscrew 242 secured to a fixed bracket 244, which displaces cam lug232.into the position shown in full lines in Fig. '7 whereby the spring226 closes valve 2I0.

Parts 50a, 58a, 60a, 80a, I I0a etc., are similar to parts 50, 58, 60,80, I I0 etc., of the preferred form of the invention, wherefore furtherdescription of their construction is deemed unnecessary. However it maybe noted that the cam roller I50a is mounted on a stud I52a on arm I,54afastened on a stud I 56a supported in an extension I58a of arm 50a. Atorsion spring I62a, which has one end fixed in the head of stud I56aand its other end secured in arm I54a, maintains the lug I84a on armI54a against a stop lug I66a on extension I 58a. When cam lug I'I0apasses over cam roller I50a while .the slide 60a is moving in thedirection shown by the arrow, the angular position of cam 234 remainsthe same. When it returns to initial position, cam lug IIIla engageswith cam roller I500, and cam 234 is thereby moved to the position shownin broken lines (Fig. 7), thereby opening valve 2I0 and releasing thepartial vacuum formed in the space between the suction cup 200 and thewrapping material W, so that slippage of the latter as it is wrappedaround an article P is prevented.

It should be pointed out, however, that when the package or article P isbeing delivered to the .lifter table 58a and thereby displaces the backtension plate 202 in the direction of the arrow and presses the wrapperW against the suction cup 200 a partial vacuum is formed in the latterwhich prevents displacement of the wrapper W while it is folded aboutthe girth of article P by mechanism similar to that shown in Figs. 1 and2. The partial vacuum is maintainedin suction cup 200 while lifter tableis swung upwardly to a horizontal position from the inclined positionrepresented in Fig. 7, and until the cam lug 232 engages the roller 222while in-the dotted position shown, the lifter table then being at itshorizontal position. Then while the lifter table swings downwardly tothe position shown in Fig. 7, the stop screw 242 returns the cam lug 232to the position shown in full lines and thereby permits spring 226 toclose valve 232. It should be noted that to prevent excessivedisplacement of cam lug 232 by the impact on stop screw 242 a stop I68ais provided on slide 60a.

The lap roller I is supported in the free ends of arms I 9| carried bybell cranks I92 loosely mounted on the shaft 52. Links I93 connect thebell cranks I92 to arms I94 fastened on shaft 34. An extension on one ofthe arms I94 is connected by a link I95 to a cam lever I96 fulcrumed ona stud I91 supported in the side frame I0. Cam lever I96 is providedwith a cam roller engaging a cam track I98 in a cam I99 fastened onshaft I 2. The shape of the cam track is such that the loop roller I90will be lowered slowly without dwelling, as in prior machines, at apoint midway of its descent while the wrapping material is being cut.With the present cam the speed with which the paper is pulled down bythe lap roller is reduced approximately 50% during this part of thecycle and instead of a jerky motion there will be a continuous dragwhich, in con-- junction with the improved construction of the backtension plate, will greatly reduce lap variations and compression ofsoft loaves.

What is claimed is:

1. In a wrapping machine, the combination with a support adapted toreceive an article, of mechanism for delivering an article to saidsupport and folding a wrapper about the girth thereof while it ispositioned upon said support, and a device for holding a portion of thewrapper while it is being folded about the girth of said article, amovable feeler arranged to be engaged and displaced by an articleadvanced by said mechanism, and instrumentalities controlled by saidfeeler for operating said device when said feeler is displaced by anarticle being delivered to said support.

2. In a wrapping machine, the combination with a support adaptedtoreceive an article, of mechanism for delivering an article to saidsupport. and folding a wrapper about the girth thereof while it ispositioned upon said support, and a device for suctionally holding aportion of the wrapper while it is being folded about the girth of saidarticle, said device. including a suction cup arranged to engage aportion of the wrapper being folded by said mechanism about the girth ofthe article and thereby create suctional adhesion of said 'wrapperportion to said cup, and instrumentalities for relieving the suctioncreated in said cup to release said wrapper portion.

3. In a wrapping machine, the combination with a vertically movablelifter table adapted to support an article to be wrapped and transportit from one level to another level, of a back tension plate mounted onsaid table in position to engage and be displaced rearwardly on saidtable by an article delivered to said table, a device supported on saidplate in position to engage and suctionally hold a wrapper, a pusher fordelivering an article to said table at one level thereof, means forpositioning wrapping material in front of said table at the level atwhich said pusher delivers the article thereto whereby said wrappingmaterial will be displaced o ard said plate by the article delivered tosaid table by said pusher and be suctionally held by said device, saiddevice including a suction cup arranged on said plate in position toengage theportion of said wrapper displaced toward said plate during thedelivery of the article to said table and thereby suctionally hold saidwrapper portion, and instrumentalitiesfor relieving the suction in saidcup when said'tabfihas transported said article to the other of saidlevels.

4. In a wrapping machine, the combination with a vertically movablelifter table adapted tosupport an article to be wrapped and transport itfrom one level to another level, of a back tension plate mounted on saidtable in position to engage and be displaced rearwardly on said table byan article delivered to said table, a device supported on said plate inposition to engage and suctionally hold a wrapper, a pusher fordelivering an article to said table at one level thereof, means forpositioning wrapping material in front of said table at the level atwhich said r pusher delivers the article thereto whereby said wrappingmaterial will be displaced toward said plate by the article delivered tosaid table by said pusher and be suctionally held by said device, amovable feeler arranged to be engaged and displaced by an articlepositioned in front of said pusher, and mechanism controlled by saidfeeler for connecting said device to a source of suction when saidfeeler is displaced by an article positioned in front of said pusher.

5. In a wrapping machine, the combination with a vertically movablesupport adapted to transport an article from one level at which anarticle is delivered to said support to another level, of means forsupporting wrapping material in front of the level at which said supportreceives an article whereby the article will be partially enfolded inthe wrapping material during its delivery to said support, a backtension plate mounted on said support and adapted to be displacedrearwardly thereon by an article deliving the delivery of the article tothe support and while said support moves to the other of said levels, aieeler arranged in the path of an article being delivered to saidsupport and adapted to be displaced by said article, and mechanismcontrolled by said feeler for connecting said device to a source ofsuction when the feeler is displaced by an article.

6. In a wrapping machine, the combination with a vertically movablesupport adapted to transport an article from one level at which anarticle is delivered to said support to another level, of means forsupporting'wrapping material in front of the level at which said supportreceives an article whereby the article will be partially enfolded inthe wrapping material during its delivery to said support, a backtension plate mounted on said support and adapted to be displacedrearwardly thereon by an article delivered to the support, a suctiondevice arranged on said plate in position to engage and suctionally holda portion of the wrapping material during the delivery of the article tothe support and while said support movesto the other of said levels, afeeler arranged in the path of an article being delivered to saidsupport and adapted to be displaced by said article, and mechanismcontrolled by said feeler for connecting said device to a source ofsuction when the feeler is displaced by an article, andinstrumentalities for disconnecting said device from the source ofsuction when said support reaches the other of said levels.

7. In a wrapping machine, the combination with a support adapted toreceive an article, means for draping wrapper material in front of saidsupport, mechanism for pushing an article into said wrapper material andon to said support to enfold the article in the wrapper material, a backtension plate movably mounted on said support resisting the movement ofsaid article on to said support and tending to hold. the wrappermaterial against said article while said article displaces said platerearwardly during delivery by said mechanism to said support, andperiodic means acting in timed relation to the movement of said pusherfor temporarily securing said wrapper to said back tension plate tosecure said wrapper against sliding movement between said back tensionplate and the adjacent face of said article, a device for moving saidplate forwardly on said support to advance the article enfolded inwrapping material from said support, and instrumentalities operated bythe forward movement of said plate for releasing the wrapper from saidplate.

8. In a wrapping machine, the combination with a movable support adaptedtoreceive an. -,article, devices imparting periodic movement to andenfold the article therein as a result of the movement of said support,a back tension plate resisting the movement of said article on to saidsupport and tending to hold the wrapper material against said, article,and means operating in timed relation tothe movement of said support fortemporarily securing said wrapper to said back tension plate to securesaid wrapper against slippage between said back tension plate and theadjacent face of said article, said means operating in timed relationand including suction devices and instrumentalities for periodicallyrendering said devices inoperative.

9. In a wrapping machine, the combination with a lifter table having ato and fro motion in a generally vertical direction and adapted tosupport an article to be wrapped, and be moved from one level at whichan article is delivered to the table to another level at which thewrapped article is removed from the table, of a pusher for advancing anarticle on to the table, a back tension plate slidably mounted on saidtable in position to engage and be displaced rearwardly by an articledelivered to the table by the pusher, devices for positioning a wrapperbetween said support and pusher to be folded about the article deliveredto the table by the pusher, suction means on the wrapper engaging faceof the back tension plate for preventing slippage of the wrapper whileit is being folded about the article, and a device for interrupting thesuction in said means after the table has been moved to the level atwhich the wrapped article is removed from the table.

10. In a wrapping machine, the combination with a lifter table having ato and fro motion in a generally vertical direction and adapted tosupport an article to be wrapped, and be moved from one level at whichan article is delivered to the table to another level at which thewrapped article is removed from the table, of a pusher for advancing anarticle on to the table, a back tension plate slidably mounted on saidtable in position to engage and be displaced rearwardly by an articledelivered to the table by the pusher, devices for positioning a wrapperbetween said support and pusher to be folded about the article deliveredto the table by the pusher, suction means on the wrapper engaging faceof the back tension plate for preventing slippage of the wrapper whileit is being folded about the article, and a device for thereafterinterrupting the suction in said means prior to the removal of thewrapped article from the table.

THORMOD JENSEN.

